Centronics Parallel Inteface Standard

Signal name	pin(s)	Source	Category	       Description
Data strobe	1, 19	  IBM	  Timing    A 1 microsec pulse to clock data
Data 1		2, 20	  IBM	  Data	    Each one of these leads provides
Data 2		3, 21	  IBM	  Data	    for a single bit of a data
Data 3		4, 22	  IBM	  Data	    character.	A high represents a
Data 4		5, 23	  IBM	  Data	    1; a low represents a 0.
Data 5		6, 24	  IBM	  Data
Data 6		7, 25	  IBM	  Data
Data 7		8, 26	  IBM	  Data
Data 8		9, 27	  IBM	  Data
Acknowledge	10, 28	  Ptr	  Control   Indicates reception of a character
Busy		11, 29	  Ptr	  Control   Printer cannot recieve more data.
PE		12	  Ptr	  Control   Printer out of paper.
Select		13	  Ptr	  Control   Indicates that printer is selected.
0 volts 	14	  Ptr	  Ground    Signal ground reference.
OSCXT		15	  Ptr	  ----	    A 100/200 kHz signal
0 volts 	16	  N/A	  Ground    Signal ground reference.
Chassis ground	17	  Ptr	  Ground    Frame ground for electrical safety
+5 volts	18	  Ptr	  ----	    Positive voltage.
Input prime	31, 30	  IBM	  Control   Resets printer.
Fault		32,	  Ptr	  Control   Indicates a printer fault condition
Press any key when done.	Press F1 for help!